Soluble epoxide hydrolase inhibitors from Docynia indica (Wall.) Decne

• Published in: Natural product research 2021-12, Vol.35 (23), p.5403-5408
• Main Authors: Xuan Duy, Le, Le Ba, Vinh, Gao, Dan, Hoang, Vu Dinh, Quoc Toan, Tran, Yang, Seo Young, Duy Quang, Dao, Kim, Young Ho, Cuong, Nguyen Manh
• Format: Article
• Language: English
• Subjects: 3-aryl dihydroisocoumarin; 3S-thunberginol C 6-O-β-D-glucopyranoside; Benzoic acid; Bioactive compounds; boat-like conformer; CD spectrum; Density functional theory; DFT; Docynia indica; Epoxide hydrolase; Fruits; Herbal medicine; Medicinal plants; NMR; Nuclear magnetic resonance; soluble epoxide hydrolase; Staphylococcal enterotoxin H
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2020.1774759

Nine bioactive compounds, including one new dihydroisocoumarin glycoside, 3S-thunberginol C 6-O-β-D-glucopyranoside (1a/1b), were isolated by chromatographic separation from the fruits of the Vietnamese medicinal plant Docynia indica (Wall.) Decne. 3S-thunberginol C 6-O-β-D-glucopyranoside was determined as a mixture of boat-like conformers based on NMR evidence and density functional theory (DFT) calculations. The in vitro inhibition of soluble epoxide hydrolase (sEH) by the isolated compounds was comparable to that of AUDA (positive control), yielding IC 50 values ranging from 10.0 ± 0.6 to 88.4 ± 0.2 µM. Among isolated compounds, 3-methoxy-4-hydroxy-benzoic acid (7) and 2′,6′-dihydroxy 3′,4′-dimethoxychalcone (9) were identified as a potent inhibitor of sEH, with IC 50 values of 19.3 ± 2.2 and 10.0 ± 0.6 mM, respectively. These results suggest that the fruits of D. indica may be useful as daily supplements for the prevention of cardiovascular and other sEH-related diseases.